Not applicable.
1. Field of the Invention
This invention relates to underwater vehicle noses, and more particularly, to an unmanned underwater vehicle nose having an improved ability to withstand high-shock conditions resulting from collisions.
2. Description of the Prior Art
Unmanned underwater vehicles (UUVs) perform a wide range of missions and come in many shapes and sizes, and generally consist of several sections, attached to one another by various means. Some UUVs have one or more flooded sections, inside of which oceanographic sensors and other hardware may be mounted. Owing to their size and complexity, UUVs must be handled, launched and recovered with great care. Typically, the UUV has one or more recovery fittings which allow it to be snagged and lifted onto a recovering vessel. The nose of the UUV is often the preferred location for such a recovery fitting because the nose is a low-flow area.
UUVs are also susceptible to catastrophic loss upon collisions with objects. Since UUVs travel mostly in a forward direction, their noses are the most likely section to inadvertently strike a submerged object, such as a rock, ship, submarine, launch and recovery craft, buoy, or aquatic creature. Even low-speed collisions can cause a UUV""s high-strength, yet often brittle, hull sections to crack or become misaligned, creating leak paths by which water can flood and sink the UUV.
It is known to provide UUVs, such as torpedoes and other vehicles, with frangible nose caps. These nose caps are usually designed in a manner that allows them to break away upon impact with the water in order to expose sensors or other equipment contained within the nose caps to the outside environment.
One problem with flexible nose caps is that they don""t make any provision for recovering the UUV. A recovery fitting cannot be positioned on the flexible nose cap itself because the nose cap isn""t strong enough to support lifting of the vehicle.
What is needed, however, is a feature for a UUV that provides increased collision protection for the UUV but at the same time allows normal recovery of the UUV.
It is an object of the present invention to provide a UUV having improved survivability after collision.
Another object of the present invention is to provide a UUV having a flexible nose cap that allows lifting by the nose cap.
Yet another object of the invention is to provide a UUV having these features that is easy to construct and cost-effective to produce.
Accordingly, the current invention provides an unmanned undersea vehicle having a flexible nose assembly. A flexible nose cap defines a hollow region therein and having a gap formed in the cap allowing fluid communication with environmental water. The flexible nose cap is joined to a bulkhead of the unmanned undersea vehicle body. At least one retrieval device is positioned on the flexible nose cap where it is accessible from the exterior of the flexible nose cap. A cable is attached between the retrieval device and the bulkhead. The invention can also include a recessed section in the nose cap having said retrieval device positioned therein.
Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawing.